Epidemiological studies have shown the importance of environmental risk factors and access to health care in childhood asthma health outcomes. Current knowledge suggests that both physical (e.g., exposure to a variety of allergens, toxins, and other factors, such as moisture, mold, and pollution) and social components (e.g., stress, family structure, and other poverty-related factors) contribute to disease etiology and expression. The proposed research builds on Dr. Lara's experience as Principal Investigator of the Allies Against Asthma in Puerto Rico demonstration project in the Luis Llorens Torres Residential Project in San Juan, Puerto Rico. This community - the largest low-cost housing project in the United States and the Caribbean - has a high- risk socio-demographic profile that can affect asthma: almost one-third of households are headed by unwed mothers; over half of residents have monthly incomes under $500; and unemployment and apathy toward educational activities is high. We propose to perform secondary analyses of a uniquely rich and existing geo-coded dataset for this Puerto Rico study, to meet the following specific aims: (1) to explore the risk factors associated with asthma prevalence, and poor symptom control and quality of life in this population, including individual- and neighborhood-level characteristics of the social environment (e.g., health care access, crime exposure) and physical environment (e.g., smoking in the household, outdoor pollution); (2) to determine whether geographic clusters of high asthma prevalence and morbidity occur in the neighborhoods studied and, if so, whether social and physical neighborhood characteristics are associated with this clustering effect; and, (3) to determine if differences exist in the effectiveness of the Allies Against Asthma intervention across subsets of the studied population with different neighborhood social and physical environment characteristics. Forty to fifty percent of Island Puerto Rican children are estimated to have childhood asthma - the highest reported prevalence of asthma of all U.S. children. The proposed study provides a unique opportunity to better understand the factors contributing to the disproportionate burden of asthma this population experiences. Our dataset contains geo-coded information on site of residence and schooling of all study participants, as well as possible neighborhood physical and social environmental contextual factors that can contribute to this asthma disparity among Puerto Ricans. The study findings can also be highly relevant to interventions to reduce asthma disparities in other Hispanic and non-Hispanic high-risk children. Forty to fifty percent of Island Puerto Rican children are estimated to have childhood asthma - the highest reported prevalence of asthma of all U.S. children. The proposed study provides a unique opportunity to better understand how environmental factors and neighborhood characteristics contribute to the disproportionate burden of asthma this population experiences. [unreadable] [unreadable] [unreadable]